Both of them were to drink from each other's toenails.

When I turned on my smartphone this morning, I received a text message. It was not an advertisement from my cell phone company, nor was it registered as an e-mail newsletter. When I saw the indication of the sender of the e-mail, I was surprised and strangely convinced at the same time. The e-mail was a reply to one I had sent more than a week ago, almost on impulse. The disciplined person did not seem to ignore the e-mail, even though I wrote finally, "You may let it go".
What did he reply to that e-mail? No. What did he think when they read that fundamentally in the first place? He thinks (the pupil who sent the e-mail) was talking weird again, or did you want to give a proper reply to the pupil who was in a good mood?
In any case, he is a gentleman. He is a man of integrity. Nothing has changed since the old days. You know that I am spoiled or have some dependence on you when I send you an e-mail.
Moreover, today is my birthday. There is no way he could have known that, so it is a mere coincidence, but it is a coincidence too good to be true. Would he be surprised if he knew my age? He might laugh and say, "You never change, no matter how old you get".

On the other hand, it is my mentor. I sent him an e-mail in early May, but he has not responded. The e-mail was not just a good-natured request but to ask for feedback on my unpublished paper. From the first e-mail I sent him in a long time, I knew he would not reply, but he never really did. I laugh at the fact that it is very typical of him. I'm sure he'll say, "Did you read my e-mail?" I bet if I asked him, he would reply, "I did, but I haven't responded". It always is. E-mails on business that require a reply rarely have it. He never changes too.

One of the two is the one who never leaves an e-mail from me untouched, no matter how trivial the content. Or regardless of how long the time interval between replies. The other is someone who rarely responds to e-mails that say required. I feel that if both of them were to drink from each other's toenails, they would find a balance in their personalities.